Patrick Foye, executive director of The Port Authority of New York and New Jersey, listens at a news conference in October 2013.

Bloomberg News

Legislative testimony from a Port Authority of New York and New Jersey official who helped reverse the George Washington Bridge lane closures will be postponed as federal prosecutor continue to investigate the matter.

Pat Foye, the executive director of the Port Authority, was scheduled to testify before the New Jersey Legislative Select Committee on Investigation on Tuesday. U.S. Attorney Paul Fishman requested Wednesday that the committee hold off on Mr. Foye’s testimony, as they also did in May.

“Our office is requesting again that his appearance before the committee be postponed,” Mr. Fishman wrote in a letter to the committee’s legal counsel, a copy of which was viewed by The Wall Street Journal.

Mr. Fishman didn’t specify why he was making the request. Federal prosecutors have been examining if laws were broken by the bridge closures last year and have been calling witnesses in to testify before a grand jury convened for the matter.

Legislative staffers informed the committee of the postponement Wednesday, but didn’t indicate a new date. The co-leaders of the committee said they will accommodate Mr. Fishman’s request.

“We are being careful with the U.S. attorney’s investigation,” said Sen. Majority Leader Loretta Weinberg, the committee’s co-head. “Our attorneys certainly don’t call witnesses if he wishes to call them first.”

A spokeswoman for Mr. Fishman declined to comment on the letter.

In addition to Mr. Foye, Port Authority commissioner William “Pat” Schuber was scheduled to testify before the committee in Trenton on Tuesday. The committee has called three witnesses so far as it seeks to investigate who closed the bridge lanes last year and why.

In September, Mr. Foye ordered the end of the lane closures on the fifth day, and raised concerns about them in a letter sent to the Christie administration. No one has been accused of wrongdoing in the probes so far.